The young Sami wants to free his world, which has turned into a sea of ice due to a climate catastrophe, from the monstrous Glajes that have driven people into cities surrounded by high walls. In their search for ways to achieve their goal, Sami and his friends stumble upon the hideout of the ice pirates and find new allies in them. From the leader of the ice pirates, the group learns that the answer to their questions is likely to be found in a mysterious forest of amphibious trees. However, to cross it, they need an airship, as the world is inhabited by countless Glajes. They set off to acquire such a ship, but are then attacked by cannibals living in the ice desert.